The strategies of Inherently Safer Design (ISD) provide a conceptual approach in order to design equipment and processes with substantially improved safety level. However, this may lead to a less economically attractive design. This study aimed to obtain optimal decision parameters of a reactor network system to produce allyl chloride. The objective functions were the risk level, including the severity and the frequency of the accidents, which were associated with the hazards in the network and the economic profit of the process. Based on this optimization approach, an array of optimal solutions (called Pareto front) was obtained as a trade-off between the objectives under investigation. A final design point was ultimately selected using Shannon's entropy and Bellman-Zadeh's techniques of decision making in a fuzzy environment. Results showed that the optimum reactor network leads to a highly complex system and more process control difficulties. This result was inconsistent with the simplification strategy of Inherently Safer design. In order to deal with this problem, a sensitivity analysis was performed that yielded a decision guide to decide about the desirable level of the risk as well as the optimum design.